TaOx-Capped Pt Nanoparticles As Active and Durable Electrocatalysts for Oxygen Reduction

Thursday, May 15, 2014: 09:00
Floridian Ballroom F, Lobby Level (Hilton Orlando Bonnet Creek)


Here we demonstrate the formation of unique structure of TaOx-capped Pt nanoparticles on a Pt/TaOx/GC electrocatalyst (Fig. 1), where at first tantalum oxide (TaOx)and next Pt nanoparticles were electrodeposited on the glassy carbon (GC) substrate, for an oxygen reduction. The surface characterizations show that the nanoparticles of TaOx deposit homogeneously on the GC surface, forming a thin layer and surprisingly, the Pt nanoparticles do not exactly deposit on the top layer of the TaOx, i.e., Ta2O5 but inside their framework and consequently a unique assembly of the TaOx-capped Pt particles is fabricated. The analyses using XPS spectra indicate electronic interactions of TaOxwith the GC, as well as with the Pt nanoparticles. The electrochemical measurements conducted by cyclic voltammetry and rotating ring-disk electrode voltammetry reveal that the novel electrocatalyst possesses an enhanced activity for an oxygen reduction reaction, without any loss of performance even after 250,000 cycles (1,111 h) of a durability test. The plausible reasons for the remarkable activity and durability of this electrocatalyst are proposed.

 Fig. 1 Schematic illustrations of (a) Pt deposited on a TaOx-modified GC surface with a TaOx framework, (b) O2 adsorption on Pt-TaOxinterface and (c) bonding formation of Ta with GC and Pt.


The present research was financially supported by Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.


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